tax credit vs decrease

tax credit and decrease both are nouns.

Word	Noun	Adjective	Verb	Adverb
tax credit	Yes	No	No	No
decrease	Yes	No	Yes	No

As nouns, decrease is a hypernym of tax credit; that is, decrease is a word with a broader meaning than tax credit:

tax credit: a direct reduction in tax liability (not dependent on the taxpayer's tax bracket)
decrease: the act of decreasing or reducing something

Other hypernyms of tax credit include diminution, reduction, step-down.

tax credit (noun)	decrease (noun)
a direct reduction in tax liability (not dependent on the taxpayer's tax bracket)	the act of decreasing or reducing something
	the amount by which something decreases
	a change downward
	a process of becoming smaller or shorter

tax credit (verb)	decrease (verb)
	decrease in size, extent, or range
	make become smaller